During some of his development, Christian Weiske found the tests for a project he was working on too slow for comfort and figured there had to be a way to find the root cause:

Running the specific test cases for the part of the application you're working on is easy and fast, but that does not tell you when changes in part A of the app break part B - which happened several times, and all just because I didn't want to wait 45 seconds again and again. So a solution was badly needed; tests should be as fast as possible; preferably < 10 seconds. Before being able to make the slow tests faster, I had to find out which of the 80 tests were slow.

Tools like Jenkinks give more detail on test runs, but a normal PHPUnit install won't. So, he came up with a method that uses Phing's phpunitreport task to generate extra reporting easily. Here's some example screenshots: test results summary, test detail and single page views of the same sort of data.